Oil separator and method of manufacturing the same

ABSTRACT

An oil separator configured to separate oil from refrigerant in a refrigeration system is disclosed. For example, the oil separator may be deployed in a heat exchange system configured to liquefy one or more fluids that are gaseous at ambient temperature and pressure. By virtue of its design and method of manufacture, the oil separator may reduce costs associated with manufacture, reduce failure to leakage, reduce misalignment of components that impair function and/or result in other undesirable effects (e.g., undesirable noise during operation, etc.).

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application claims the priority benefit under 35 U.S.C. §371 of international patent application no. PCT/IB2010/05371535, filed Aug. 17, 2010, which claims the priority benefit under 35 U.S.C. §119(e) of U.S. provisional patent application No. 61/245,806, filed on Sep. 25, 2009, the contents of each of which are herein incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to an oil separator configured to separate oil from refrigerant, and a method of manufacturing the same.

2. Description of the Related Art

Oil separators configured to separate refrigerant from oil in a refrigeration system are known. However, conventional oil separator designs typically require fabrication using a relatively large amount of separate components that must be individually modified at manufacture. This increases the cost of manufacturing such oil separators (in manpower and materials), and may hinder reliability, usability, and/or efficiency.

SUMMARY OF THE INVENTION

One aspect of the invention relates to an oil separator configured to separate oil from refrigerant. In one embodiment, the oil separator comprises a cylindrical housing, a first annular seat, a first screen, a second annular seat, a second screen, and coalescing material. The cylindrical housing has a first end and a second end, and forms an oil outlet opening, an inlet opening, and a refrigerant outlet opening. The oil outlet opening is formed in a sidewall of the cylindrical housing near the first end of the cylindrical housing, and is configured to release oil that has been separated from refrigerant within the cylindrical housing out of the cylindrical housing. The inlet opening is formed in the sidewall of the cylindrical housing spaced away from the oil outlet opening toward the second end of the cylindrical housing, and is configured to receive a flow of refrigerant mixed with oil into the oil separator. The refrigerant outlet opening is formed at the second end of the cylindrical housing, and is configured to release refrigerant from which oil has been removed out of the cylindrical housing. The first annular seat is disposed on an inner surface of the cylindrical housing between the inlet opening and the refrigerant outlet opening, and is a fixed annular protrusion from the inner surface of the cylindrical housing. The first screen is seated on a side of the first annular seat facing toward the second end of the cylindrical housing, and has a shape that corresponds to the cross section of the cylindrical housing. The second annular seat is disposed on an inner surface of the cylindrical housing between the first annular seat and the refrigerant outlet opening, and is a fixed annular protrusion from the inner surface of the cylindrical housing. The second screen is seated on a side of the second annular seat facing toward the first end of the cylindrical housing, and has a shape that corresponds to the cross section of the cylindrical housing. The coalescing material is disposed within the cylindrical housing between the first screen and the second screen such that the coalescing material applies a force to the first screen that seats the first screen on the first annular seat, and applies a force to the second screen that seats the second screen on the second annular seat.

Another aspect of the invention relates to a method of manufacturing an oil separator configured to separate oil from refrigerant. In one embodiment, the method comprises (a) obtaining an open, hollow cylinder having a first end and a second end; (b) forming an oil outlet opening in a sidewall of the cylinder near the first end of the cylinder, the oil outlet opening being configured to release oil that has been separated from refrigerant within the cylinder out of the cylinder; (c) forming an inlet opening in the sidewall of the cylinder spaced away from the oil outlet opening toward the second end of the cylinder, the inlet opening being configured to receive a flow of refrigerant mixed with oil into the oil separator; (d) enclosing the first end of the cylinder by spinning the first end of the cylinder; (e) forming a first annular seat on an inner surface of the cylinder between the inlet opening and the refrigerant outlet opening, wherein the first annular seat is a fixed annular protrusion from the inner surface of the cylinder; (f) subsequent to operation (e), seating a first screen within the cylinder on a side of the first annular seat facing toward the second end of the cylinder, wherein the first screen has a shape that corresponds to the cross section of the cylinder; (g) subsequent to operation (f), inserting coalescing material into the cylinder such that the coalescing material applies a force to the first screen that seats the first screen on the first annular seat; (h) subsequent to operation (g), inserting a second screen into the cylinder such that the second screen cooperates with the first screen to capture the coalescing material within the cylinder; (i) subsequent to operation (h), forming a second annular seat on the inner surface of the cylinder between the first screen and the second end of the cylinder such that the coalescing material applies a force to the second screen that seats the second screen on the second annular seat, wherein the second annular seat is a fixed annular protrusion from the inner surface of the cylinder.

Yet another aspect of the invention relates to an oil separator configured to separate oil from refrigerant. In one embodiment, the oil separator comprises a cylindrical housing having a first end and a second end, the cylindrical housing forming: means for releasing oil that has been separated from refrigerant within the cylindrical housing out of the cylindrical housing; means for receiving a flow of refrigerant mixed with oil into the cylindrical housing; and means for releasing refrigerant from which oil has been removed out of the cylindrical housing. The oil separator further comprises means for coalescing oil out of a flow of refrigerant and oil; first means for capturing the means for coalescing within the cylindrical housing, wherein the first means for capturing is positioned between the means for receiving and the means for releasing refrigerant; means for retaining the first means for capturing within the cylindrical housing, wherein the first means for capturing is seated on a side of the means for retaining that faces the second end of the cylindrical housing; second means for capturing the means for coalescing within the cylindrical housing, wherein the second means for capturing is positioned on a side of the means for coalescing opposite the first means for capturing; and means for retaining the second means for capturing within the cylindrical housing, wherein the second means for capturing is seated on a side of the means for retaining that faces the first end of the cylindrical housing.

These and other objects, features, and characteristics of the present invention, as well as the methods of operation and functions of the related elements of structure and the combination of parts and economies of manufacture, will become more apparent upon consideration of the following description and the appended claims with reference to the accompanying drawings, all of which form a part of this specification, wherein like reference numerals designate corresponding parts in the various figures. In one embodiment of the invention, the structural components illustrated herein are drawn in proportion. It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only and are not a limitation of the invention. In addition, it should be appreciated that structural features shown or described in any one embodiment herein can be used in other embodiments as well. It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only and are not intended as a definition of the limits of the invention. As used in the specification and in the claims, the singular form of “a”, “an”, and “the” include plural referents unless the context clearly dictates otherwise.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a front elevation view of an oil separator, in accordance with one or more embodiments of the invention;

FIG. 2 illustrates a side view of an oil separator, according to one or more embodiments of the invention;

FIG. 3 illustrates a bottom view of an oil separator, in accordance with one or more embodiments of the invention;

FIG. 4 illustrates a sectional view of an oil separator, according to one or more embodiments of the invention; and

FIG. 5 illustrates a method of manufacturing an oil separator, in accordance with one or more embodiments of the invention.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

FIGS. 1-4 illustrate an oil separator 10 configured to separate oil from refrigerant. The oil separator 10 is configured to separate oil from refrigerant in a refrigeration system. For example, oil separator 10 may be deployed in a heat exchange system configured to liquefy one or more fluids that are gaseous at ambient temperature and pressure. By virtue of its design and method of manufacture, oil separator 10 may reduce costs associated with manufacture, reduce failure to leakage, reduce misalignment of components that impair function and/or result in other undesirable effects (e.g., undesirable noise during operation, etc.). FIGS. 1-3 depict front, side, and bottom elevation views, respectively, of oil separator 10. FIG. 4 depicts a sectional view of oil separator 10 taken along section line 4-4 shown in FIG. 3.

As can be seen in FIGS. 1-4, oil separator 10 includes a cylindrical housing 12. The cylindrical housing 12 is hollow, and is enclosed at each of a first end 14 and a second end 16. In one embodiment, cylindrical housing 12 has a wall thickness of about 0.062 inches, an inner diameter of about 1.0 inches, and/or a length of about 3.5 inches. The cylindrical housing 12 is formed from a chemically and structurally stable material that will facilitate the functionality attributed herein to oil separator 10. For example, in one embodiment, cylindrical housing 12 is formed from a metallic material, such as copper, aluminum, and/or other metallic materials.

The cylindrical housing 12 forms an oil outlet opening 18, an inlet opening 20, and a refrigerant outlet opening 22. An oil outlet line 24 communicates with the interior of cylindrical housing 12 via oil outlet opening 18. An inlet line 26 communicates with the interior of cylindrical housing 12 via inlet opening 20. A refrigerant outlet line 28 communicates with the interior of cylindrical housing 12 via refrigerant outlet opening 22.

The oil outlet opening 18 is formed in the side wall of cylindrical housing 12 at or near first end 14. The oil outlet line 24 is mated to cylindrical housing 12 at oil outlet opening 18 such that oil separated from refrigerant within cylindrical housing 12 is released from cylindrical housing 12 through oil outlet opening 18 and oil outlet line 24. In one embodiment, oil outlet line 24 conveys the oil released from cylindrical housing 12 back to the system from which it came (e.g., a refrigerator compressor). The oil outlet opening 18 may be formed in the sidewall of cylindrical housing 12 by extrusion drilling The diameter of oil outlet opening 18 may be about 0.032 inches. The oil outlet line 24 may be formed from copper tubing, aluminum tubing, and/or other tubular materials.

The inlet opening 20 is formed in the side wall of cylindrical housing 12 between oil outlet opening 18 and second end 16. The inlet line 26 is mated to cylindrical housing 12 at inlet opening 20 such that a flow of refrigerant mixed with oil is received into cylindrical housing 12 from inlet line 26 through inlet opening 20. As can be seen in FIG. 2, inlet opening 20 is formed in cylindrical housing 12 such that the flow of refrigerant mixed with oil is introduced into cylindrical housing 12 along a path that is off-axis with respect to a longitudinal axis through cylindrical housing 12. The inlet opening 20 may be formed in the sidewall of cylindrical housing 12 by milling, and/or other techniques. The diameter of inlet opening 20 may be about 0.25 inches. The inlet line 26 may be formed from copper tubing, aluminum tubing, and/or other materials.

The refrigerant outlet opening 22 is formed at second end 16 of cylindrical housing 12. In one embodiment, refrigerant outlet opening 22 is formed at or near the longitudinal axis of cylindrical housing 12. This may enhance flow through refrigerant outlet opening 22. However, this configuration is not intended to be limiting and refrigerant outlet opening 22 may be formed at other locations at or near second end 16 of cylindrical housing 12. The refrigerant outlet line 28 is mated to cylindrical housing 12 at refrigerant outlet opening 22 such that refrigerant from which the oil has been removed flows out of cylindrical housing 12 through refrigerant outlet opening 22 and refrigerant outlet line 28. In one embodiment, refrigerant outlet opening 22 is formed at second end 16 during enclosure of second end 16 of cylindrical housing 12. Specifically, second end 16 is enclosed by a spinning process, and a lip 30 that forms refrigerant outlet opening 22 is formed during this spinning process. By virtue of the formation of lip 30, a faying surface of refrigerant outlet opening 22 at which refrigerant outlet line 28 is mated to refrigerant outlet opening 22 is enlarged. The diameter of inlet opening 20 may be about 0.25. The refrigerant outlet line 28 may be formed from copper tubing, aluminum tubing, and/or other materials.

Referring primarily to FIG. 4, a filter 32 is seated within cylindrical housing 12 between inlet opening 20 and oil outlet opening 18. The filter 32 is configured to filter oil that has entered cylindrical housing 12 through inlet opening 20 before the oil is released from cylindrical housing 12 through oil outlet opening 18. The filter 32 may be seated within cylindrical housing 12 by friction fit, by press fit, by an adhesive, by weld, and/or by other techniques for fixing the position of filter 32 within cylindrical housing 12.

The oil separator 10 includes a first annular seat 34 and a second annular seat 36 disposed along the inner surface of cylindrical housing 12. Each of first annular seat 34 and second annular seat 36 are a fixed annular protrusion from the inner surface of cylindrical housing 12. These annular protrusions may each be continuous, or substantially continuous, which may provide a more secure seat in comparison with seats formed from a plurality of protrusions (e.g., as a series of three or more tabs extending into cylindrical housing 12). In one embodiment, first annular seat 34 and second annular seat 36 are formed integrally with cylindrical housing 12 in that they are formed from the actual material of cylindrical housing 12. For example, each of first annular seat 34 and second annular seat 36 can be formed by rolling a bead in cylindrical housing 12 that runs around cylindrical housing 12.

A first screen 38 is seated on first annular seat 34 on a side of first annular seat 34 facing toward second end 16. The first screen 38 has a shape that corresponds to the cross section of cylindrical housing 12. In one embodiment, first screen 38 has a shape such that any substance passing from one side of first screen 38 to the other side of first screen 38 within cylindrical housing 12 must pass through first screen 38 (and not around a side thereof). In order to facilitate the fixing of first screen 38 in place, the shape of first screen 38 may be slightly larger than the cross section of cylindrical housing 12. This will enable first screen 38 to be held in place within 12 by press fit, as well as the seating on first annular seat 34 and other forces that hold first screen 38 in place (discussed below). In the embodiment in which first screen 38 is slightly larger than the cross section of cylindrical housing 12, first screen 38 will bow upon installation within cylindrical housing 12, which can be seen in FIG. 4. The first screen 38 may be formed from stainless steel, aluminum, and/or other materials.

A second screen 40 is seated on second annular seat 36 on a side of oil outlet line 24 facing toward first end 14. The shape of second screen 40 corresponds to the cross section of cylindrical housing 12. In one embodiment, the shape of second screen 40 is the same, or substantially the same, as the shape of first screen 38. The second screen 40 may be formed from stainless steel, aluminum, and/or other materials.

A coalescing material 42 is disposed within cylindrical housing 12 between first screen 38 and second screen 40. The coalescing material 42 is captured within cylindrical housing 12 by first screen 38 and second screen 40. The coalescing material 42, in turn, applies forces to first screen 38 and second screen 40 that seats first screen 38 on first annular seat 34 and that seats second screen 40 on second annular seat 36, respectively. The coalescing material 42 may include, for example, a porous material, such as a wool, a sponge, and/or other porous materials. The coalescing material 42 may be formed from a metallic material, such as stainless steel, aluminum, and/or other materials.

A ferrel 44 is disposed within cylindrical housing 12. The ferrel 44 has an annular cross section that is smaller in diameter than the inner diameter of cylindrical housing 12. In one embodiment, the outer diameter of ferrel 44 is about 0.75 inches. At one end, ferrel 44 includes an annular rim 46 that extends from ferrel 44 in a direction transverse to a longitudinal axis of ferrel 44. To fix the position of ferrel 44 within cylindrical housing 12, rim 46 is seated on first annular seat 34. The rim 46 is held in place on rim first annular seat 34 by first screen 38. The capture of rim 46 of ferrel 44 between first annular seat 34 and first screen 38 provides a more secure fixture of ferrel 44 within cylindrical housing 12 than embodiments in which rim 46 is only engaged on one side. This may, for example, reduce noise associated with movement of ferrel 44 within cylindrical housing 12 during use.

In use, a flow of refrigerant and oil mixed together enter cylindrical housing 12 through inlet opening 20. The refrigerant is in a gaseous state, and the oil and/or other impurities may be in a liquid state (as a vapor within the refrigerant) and/or a gaseous state. The flow may be somewhat pressurized.

Upon entering cylindrical housing 12, the refrigerant/oil mix is directed in a flow path around and around the inner surface of cylindrical housing 12. The flow path is formed by the inner surface of cylindrical housing 12, and ferrel 44. By virtue of the generally circular flow path formed by these components, and the pressurization of the flow as it enters cylindrical housing 12, oil within the refrigerant is centrifuged out to the inner surface of cylindrical housing 12. As the oil reaches the inner surface of cylindrical housing 12, the oil condenses on the inner surface of cylindrical housing 12, and slides down to first end 14 through filter 32.

Refrigerant that has been centrifuged in this manner eventually passes through ferrel 44 and first screen 38 toward second end 16. In doing so this refrigerant, which is still mixed with some oil, passes through coalescing material 42. The coalescing material 42 draws even more of the oil of the refrigerant by causing condensation of the oil on coalescing material 42. This condensed oil eventually will fall, by virtue of gravity, back toward first end 14 through first screen 38, ferrel 44, and filter 32.

After passing through coalescing material 42 and second screen 40, the refrigerant is released from cylindrical housing 12 through refrigerant outlet opening 22. By virtue of the previous centrifuging, and traversal of coalescing material 42, the refrigerant released from cylindrical housing 12 through refrigerant outlet opening 22 will be substantially free from oil and/or other impurities.

FIG. 5 illustrates a method 48 of manufacturing an oil separator configured to separate oil from refrigerant. The operations of method 48 presented below are intended to be illustrative. In some embodiments, method 48 may be accomplished with one or more additional operations not described, and/or without one or more of the operations discussed. Additionally, the order in which the operations of method 48 are illustrated in FIG. 5 and described below is not intended to be limiting.

At an operation 50, an open, hollow cylinder having a first end and a second end is obtained. Obtaining the cylinder may include, for example, cutting and/or otherwise preparing a length of cylindrical stock material. In one embodiment, the cylinder may for a cylindrical housing that is similar to or the same as cylindrical housing 12 (shown in FIGS. 1-4 and described above).

At an operation 52, one or more openings are formed in the cylinder obtained at operation 50. The one or more openings include openings through which refrigerant and/or oil are received into and released from the oil separator. In one embodiment, the one or more opening include an oil outlet opening and an inlet opening. The oil outlet opening is formed in the cylinder at or near the first end. The inlet opening is formed in the cylinder between the oil outlet opening and the second end of the cylinder. In one embodiment, the oil outlet opening and the inlet opening are the same as or similar to oil outlet opening 18 and inlet opening 20, respectively (shown in FIGS. 1-4 and described above).

At an operation 54, a filter is installed in the cylinder. Upon installation, the filter is positioned in the cylinder between the oil outlet opening and the inlet opening such that oil released from the oil separator filtered by the filter before being released. In one embodiment, the filter is the same as or similar to filter 32 (shown in FIG. 4 and described above).

At an operation 56, a first annular seat is formed within the cylinder. The first annular seat is a fixed annular protrusion from the inner surface of the cylinder. In one embodiment, the first annular seat is the same as or similar to first annular seat 34 (shown in FIG. 4 and described above).

At an operation 58, subsequent to operation 56, a ferrel is deposited within the cylinder. The ferrel includes a rim that extends from one end of the ferrel in a direction that is transverse to a longitudinal axis of the ferrel. As the ferrel is deposited within the cylinder, the rim of the ferrel contacts the first annular seat on a side of the first annular seat that faces toward the second end of the cylinder. In one embodiment, the ferrel is the same as or similar to ferrel 44 (shown in FIG. 4 and described above).

At an operation 60, subsequent to operation 58, a first screen is disposed in the cylinder. The first screen is installed in the cylinder to contact a side of the rim of the ferrel opposite the first annular seat. This effectively seats both the first screen and the ferrel on the first annular seat. In one embodiment, the first screen is the same as or similar to first screen 38 (shown in FIG. 4 and described above).

At an operation 62, subsequent to operation 60, a coalescing material is deposited into the cylinder. The coalescing material is deposited on a side of the first screen that faces the second end of the cylinder. In one embodiment, the coalescing material is the same as or similar to coalescing material 42 (shown in FIG. 4 and described above).

At an operation 64, subsequent to operation 62, a second screen is disposed within the cylinder on a side of the coalescing material opposite from the first screen. In one embodiment, the second screen is the same as or similar to second screen 40 (shown in FIG. 4 and described above).

At an operation 66, subsequent to operation 64, a second annular seat is formed within the cylinder. The second annular seat is a fixed protrusion from the inner surface of the cylinder. The position of the second annular seat is such that the second screen is seated on the second annular seat on a side of the second annular seat facing toward the first end of the cylinder. The second annular seat is configured such that the seating of the second screen on the second annular seat captures the coalescing material within the cylinder between the first screen and the second screen. By virtue of its capture between the first screen and the second screen, the coalescing material applies forces to the first screen and the second screen that seat the first screen and the second screen on the first annular seat and the second annular seat, respectively.

At an operation 68, the first and second ends of the cylinder are closed. By way of non-limiting example, the first and second ends of the cylinder may be spun closed.

At an operation 70, a refrigerant outlet opening is formed at or near the closed second end of the cylinder. The refrigerant outlet opening is configured to release refrigerant from the oil separator after the oil has been removed. In one embodiment, the refrigerant outlet opening is formed at least partially during the closure of the second end of the cylinder in operation 68. For example, the refrigerant outlet opening may be the same as or similar to refrigerant outlet opening 22 (shown in FIGS. 1-4 and described above).

At an operation 72, one or more lines are connected to the openings formed in the cylinder at operations 52 and 70. The one or more lines are configured to convey refrigerant and/or oil to or from the cylinder. In one embodiment, the one or more lines include an oil outlet line, an inlet line, and a refrigerant outlet line that are the same as or similar to oil outlet line 24, inlet line 26, and refrigerant outlet line 28, respectively (shown in FIGS. 1-4 and described above).

Although the invention has been described in detail for the purpose of illustration based on what is currently considered to be the most practical and preferred embodiments, it is to be understood that such detail is solely for that purpose and that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover modifications and equivalent arrangements that are within the spirit and scope of the appended claims. For example, it is to be understood that the present invention contemplates that, to the extent possible, one or more features of any embodiment can be combined with one or more features of any other embodiment. 

What is claimed is:
 1. An oil separator configured to separate oil from refrigerant, the oil separator comprising: (a) a cylindrical housing having a first end and a second end, the cylindrical housing including: (1) an oil outlet opening in a sidewall of the cylindrical housing near the first end of the cylindrical housing, the oil outlet opening being configured to release oil that has been separated from refrigerant within the cylindrical housing out of the cylindrical housing, (2) an inlet opening in the sidewall of the cylindrical housing spaced away from the oil outlet opening toward the second end of the cylindrical housing, the inlet opening being configured to receive a flow of refrigerant mixed with oil into the oil separator, and (3) a refrigerant outlet opening at the second end of the cylindrical housing, the refrigerant outlet opening being configured to release refrigerant from which oil has been removed out of the cylindrical housing; (b) a first annular seat disposed on an inner surface of the cylindrical housing between the inlet opening and the refrigerant outlet opening, wherein the first annular seat is a fixed annular protrusion from the inner surface of the cylindrical housing; (c) a first screen seated on a side of the first annular seat facing toward the second end of the cylindrical housing, wherein the first screen has a shape that corresponds to the cross section of the cylindrical housing; (d) a second annular seat disposed on an inner surface of the cylindrical housing between the first annular seat and the refrigerant outlet opening, wherein the second annular seat is a fixed annular protrusion from the inner surface of the cylindrical housing; (e) a second screen seated on a side of the second annular seat facing toward the first end of the cylindrical housing, wherein the second screen has a shape that corresponds to the cross section of the cylindrical housing; and (f) coalescing material disposed within the cylindrical housing to fill the volume of the cylindrical housing between the first screen and the second screen such that the coalescing material applies a force to the first screen that seats the first screen on the first annular seat, and applies a force to the second screen that seats the second screen on the second annular seat.
 2. The oil separator of claim 1, further comprising a ferrel having an annular rim that extends from the ferrel in a direction transverse to a longitudinal axis of the ferrel, the rim of the ferrel being seated on the first annular seat and being held in place on the first annular seat by the first screen.
 3. The oil separator of claim 1, further comprising a filter seated within the cylindrical housing between the inlet opening and the oil outlet opening such that oil must pass through the filter before being released from the cylindrical housing through the oil outlet opening.
 4. The oil separator of claim 1, wherein one or both of the first annular seat and/or the second annular seat includes an unbroken annular protrusion that runs continuously about the inner surface of the cylindrical housing.
 5. The oil separator of claim 1, wherein the cylindrical housing is closed on the first end and the second end by a structure that is formed by spinning the cylindrical material from which the cylindrical housing is formed.
 6. A method of manufacturing an oil separator configured to separate oil from refrigerant, the method comprising: (a) obtaining an open, hollow cylinder having a first end and a second end; (b) forming an oil outlet opening in a sidewall of the cylinder near the first end of the cylinder, the oil outlet opening being configured to release oil that has been separated from refrigerant within the cylinder out of the cylinder; (c) forming an inlet opening in the sidewall of the cylinder spaced away from the oil outlet opening toward the second end of the cylinder, the inlet opening being configured to receive a flow of refrigerant mixed with oil into the oil separator; (d) enclosing the first end of the cylinder by spinning the first end of the cylinder; (e) forming a first annular seat on an inner surface of the cylinder between the inlet opening and the refrigerant outlet opening, wherein the first annular seat is a fixed annular protrusion from the inner surface of the cylinder; (f) subsequent to operation (e), seating a first screen within the cylinder on a side of the first annular seat facing toward the second end of the cylinder, wherein the first screen has a shape that corresponds to the cross section of the cylinder; (g) subsequent to operation (f), inserting coalescing material into the cylinder such that the coalescing material applies a force to the first screen that seats the first screen on the first annular seat; (h) subsequent to operation (g), inserting a second screen into the cylinder such that the second screen cooperates with the first screen to capture the coalescing material within the cylinder such that the coalescing material fills the volume of the cylinder between the first screen and the second screen; (i) subsequent to operation (h), forming a second annular seat on the inner surface of the cylinder between the first screen and the second end of the cylinder such that the coalescing material applies a force to the second screen that seats the second screen on the second annular seat, wherein the second annular seat is a fixed annular protrusion from the inner surface of the cylinder.
 7. The method of claim 6, wherein one or both of the first annular seat and/or second annular seat is formed by rolling a bead in the cylinder that results in an annular protrusion the projects into the cylinder.
 8. The method of claim 6, further comprising, subsequent to operation (i), enclosing the second end of the cylinder, and forming a refrigerant outlet opening at the second end of the cylinder, the refrigerant outlet opening being configured to release refrigerant from which oil has been removed out of the cylinder.
 9. The method of claim 6, further comprising, subsequent to operation (d) but before operation (e), installing a ferrel within the cylinder, the ferrel having an annular rim that extends from the ferrel in a direction transverse to a longitudinal axis of the ferrel, wherein installing the ferrel within the cylinder includes seating the rim of the ferrel on the first annular seat so that the rim of the ferrel is held in place on the first annular seat by the first screen.
 10. The method of claim 6, further comprising, prior to operation (e), installing a filter within the cylinder between the inlet opening and the oil outlet opening such that oil must pass through the filter before being released from the cylinder through the oil outlet opening.
 11. An oil separator configured to separate oil from refrigerant, the oil separator comprising: (a) a cylindrical housing having a first end and a second end, the cylindrical housing including: (1) means for releasing oil that has been separated from refrigerant within the cylindrical housing out of the cylindrical housing, (2) means for receiving a flow of refrigerant mixed with oil into the cylindrical housing, and (3) means for releasing refrigerant from which oil has been removed out of the cylindrical housing; (b) means for coalescing oil out of a flow of refrigerant and oil; (c) first means for capturing the means for coalescing within the cylindrical housing, wherein the first means for capturing is positioned between the means for receiving and the means for releasing refrigerant; (d) means for retaining the first means for capturing within the cylindrical housing, wherein the first means for capturing is seated on a side of the means for retaining that faces the second end of the cylindrical housing; (e) second means for capturing the means for coalescing within the cylindrical housing, wherein the second means for capturing is positioned on a side of the means for coalescing opposite the first means for capturing and between the means for receiving and the means for releasing refrigerant; and (f) means for retaining the second means for capturing within the cylindrical housing, wherein the second means for capturing is seated on a side of the means for retaining that faces the first end of the cylindrical housing.
 12. The oil separator of claim 11, further comprising a ferrel having an annular rim that extends from the ferrel in a direction transverse to a longitudinal axis of the ferrel, the rim of the ferrel being seated on the means for retaining the first capturing means and being held in place on the means for retaining the first capturing means and the first capturing means.
 13. The oil separator of claim 11, further comprising a means for filing oil being released from the cylindrical housing through the means for releasing oil.
 14. The oil separator of claim 11, wherein one or both of the means for retaining includes an unbroken annular protrusion that runs continuously about the inner surface of the cylindrical housing.
 15. The oil separator of claim 11, wherein the cylindrical housing is closed on the first end and the second end by a structure that is formed by spinning the cylindrical material from which the cylindrical housing is formed. 